Antenna with elements pivotally connected to boom



J. ERVINE 3,300,784

ANTENNA WITH ELEMENTS PIVOTALLY CONNECTED TO BOOM Jan. 24, 1967 2Sheets-Sheet 1 Filed Sept. 8, 1965 INVENTOR JOHNI LEE ERVINE 40 B Z/WQ mM ATTORNEYS I Jan. 24, 1967 vmE 3,300,784

ANTENNA WITH ELEMENTS PIVOTALLY CONNECTED TO BOOM Filed Sept. 8, 1965 2sheets-sheet 2 INVENTOR JOHNIE LEE ERWN BY Z/OMQ W+ W9 ATTORNEYS UnitedStates Patent 3,300,784 ANTENNA WITH ELEMENTS PIVOTALLY CONNECTED TOBOOM Johnie Lee Ervine, 727 N. 8th, Burlington, Iowa 52601 Filed Sept.8, 1965, Ser. No. 485,707 6 Claims. (Cl. 343882) The present inventionrelates generally to an antenna structure of the type which comprises aboom and a plurality of elongated elements secured transversely to theboom, and more particularly, to a device for pivotally connecting theelements of the antenna to the boom and for selectively securing eachelement transversely of the boom and parallel to the other elements.

Heretofore, antennas such as conventional television and FM. radioantennas have been provided with antenna elements which can be pivotedinto a position generally parallel with the boom for shipping in boxeshaving a relatively small cross-sectional size. However, such antennas,before they are useful, must have the elements thereof positionedtransversely of the boom. Further, it is highly desirable to have theelements perpendicular to the boom and parallel to each other. In thisposition, the elements must be secured to the boom in a manner such thatthe elements will remain perpendicular to the boom and parallel to eachother during the use of the antenna. Storms having high winds tend tomove the elements from this desired position, and therefore, it isdesirable to provide a device whereby the elements can be pivotallyconnected to an antenna boom and securely locked into the desiredposition. P-rior devices were designed such that when the element andthe boom were connected together with sufficient force to hold themsecure in the desired position, the pivoting of the elements and boomwas only accomplished with difficulty and many times the elements werebent in trying to position them transversely of the boom. Thisdifficulty in operation of prior devices was due to the fact that manytimes the device was bent from the forceful connection of the element tothe boom in the manufacturing of the antenna or became engaged with anedge of the device which restricted the movement of the element asdesired. It is therefore further desirable that a device for pivotallyconnecting a plurality of elements to the boom of an antenna be capableof clamping forcefully the elements and boom together, but still permitfacile pivoting of the elements from a collapsed position to one inwhich the elements are transverse to the boom.

It is therefore the primary object of this invention to provide animproved device for pivotally connecting an element of an antenna to theboom whereby the element can be positioned generally parallel to theboom and moved when desired to a position generally perpendicular to theboom and secured in this last-mentioned position.

Another object of this invention is to provide an improved device forpivotally connecting an element of an antenna to an antenna boom whichwill not be deformed during the manufacture of the antenna so as torestrict the movement of the element into the desired position.

Still another object of this invention is to provide an improved devicefor pivotally connecting an antenna element to a boom which allows theelements to be pivotally rotated into a position transverse to the boomand wherein the element is locked in position and rigidly secured to theboom whereby high winds are incapable of. moving the element from thelocked position of the element.

A further object of this inventiton is to provide an improved device forpivotally connecting an antenna element to a boom which has a detentwhich is movable from a position corresponding to the alignment of theelement with the boom to a position in which the detent is positioned ina detent-receiving indentation and the element is generallyperpendicular to the boom with relative ease whereby the element can besecured to the element boom.

Still further an object of this invention is to provide an improveddevice for pivotally connecting an element to an antenna boom which isrelatively strong such that no deformaiton of the device will occurduring the connection of the element to the boom during themanufacturing of the antenna, and which is provided with a detent and adetent-receiving indentation and oppositely facing calming surfaces onboth sides of the detent-receiving indentation, respectively, wherebythe element can be moved from a position generally aligned with the boomto a position transverse of the boom with the detent positioned in thedetent-receiving indentation thereby rigidly securing the element in thelast-mentioned position to the boom.

The above-mentioned and other features and objects of this invention andthe manner of attaining them will become more apparent and the inventionitself will be best understood by reference to the following descriptionof an embodiment of the invention taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a perspective view of an antenna comprising an antenna boom, amast supporting the boom in a generally horizontal position, and aplurality of elements secured to said boom in spaced apart and parallelrelationship with each other and generally perpendicularly of the boom;

FIG. 2 is a fragmentary view of the antenna having the improved deviceof this invention mounted on the boom and securely and rigidly holdingan element transversely of the boom;

FIG. 3 is a top view of the base portion of the improved fasteningdevice of this invention;

FIG. 4 is a bottom view of the same base portion;

FIG. 5 is a side view of the same base portion showing the top surfaceof the base portion facing downwardly;

FIG. 6 is an end view of the same base portion showing the top surfacefacing downwardly and illustrating the indentation in the top surface;

FIG. 7 is an end view of said base portion opposite to that viewed inFIG. 6 and showing the top surface facing downwardly;

FIG. 8 is a view in cross-section of the boom illustrating the antennaelement in its aligned position with the boom;

FIG. 9 is a fragmentary view, partially in cross-section, of thestructure illustrated in FIG. 8 showing the antenna element moved into aposition generally perpendicular to the antenna boom whereby the antennaelement is locked into the position shown and rigidly and securelyconnected to the antenna boom;

FIG. 10 is a top view of the cap member which cooperates with the baseportion in clamping the antenna element and boom together; and

FIG. 11 is a sectional view of the base member taken substantially alongsection line 1111 of FIG. 3.

In the broader aspects of this invention, there is provided a device forpivotally connecting an antenna ele ment to a boom comprising a basemember having a flat plate portion with an upwardly facing flat surface,opposite and parallel longitudinal edges, and opposite end portions. Twostrengthening and reinforcing flange portions are integrally joined tothe plate portion adjacent the opposite edges, respectively, and extendbetween the end portions. The flange portions have oppositely andoutwardly facing camming surfaces which join the upwardly facing platesurface at their longitudinal edges, and are rounded and smoothly mergedwith the plate surface whereby the camming surfaces and the upwardlyfacing surface of the base member are continuous. The end portionsextend transversely away from the plate portion and are mounted on theboom with the plate portion spaced from the boom. The upwardly facingsurface of the plate portion has an indentation therein havingoppositely facing and upstanding abutment surfaces which form adetent-receivin-g indentation.

Referring to the drawings, and more particularly to FIGS. 1 and 2, thereis shown a conventional antenna boom 10 which is rigidly secured in agenerally horizontal position to a conventional antenna mast 12. Securedto the boom 10 in spaced apart positions, respectively, are a pluralityof antenna elements 14. Elements 14 are secured to the boom 10 at themidportions thereof and extend generally perpendicular to the boomparallel to each other. Each of the elements 14 are secured to boom 10by means of the improved fastening device 16 of this invention whichcomprises a cap member 13 and a base member 20. The specific embodimentillustrated has a rivet 22 which is used to fasten the element 14 to theboom 10. Rivet 22 passes through an opening 23 in the cap member 18, theelement r14, the base member 20 and the boom 10 and forcibly clamps theaforesaid members together between flattened end portions of the rivet22 as will be hereinafter more specifically described.

Referring now to FIGS. 3 through 7, the improved base member 20 of thedevice of this invention will now be described. Base member 20 has aflat metal plate portion 24 of substantially rectangular shape with aflat surface 26 facing away from the boom it} when the base member 20 ismounted thereon. Metal plate portion 24 has opposite and parallellongitudinal edges 23 and 3t and opposite and spaced apart end portions32 and 34. Two strengthening and reinforcing flange portions 36 and 38are joined to plate portion 24 adjacent to the opposite longitudinaledges 28 and 30, respectively, so as to extend generally perpendicularlyaway from plate portion 24 and toward boom 10 when the base member 20 ismounted thereon. Flange portions 36 and 38 extend between the oppositeend portions 32 and 34 and have oppositely and outwardly facing cammingsurfaces 4%) and 42, respectively, joining the plate surfaces 26 at thelongitudinal edges 28 and 30. Camming surfaces 49', 42 are rounded andsmoothly merge with the surface 26 of the plate portion 24 therebyforming a continuous base portion surface extending between therespective flange portions 36 and 38. End portions 32 and 34 generallyextend perpendicularly away from the plate portion 24 in the samedirection as the flange portions 36 and 38, respectively, and toward theboom 10 when the base member 20 is mounted thereon. Each of the endportions 32 and 34 has a part cylindrical surface 44 and 4-6,respectively, which is ooaxially positioned on boom 16 when the basemember 20 is mounted thereon. End portions 32 and 34 extend away fromplate portion 24 a distance greater than the extension of the flangeportions 36 and 38; and therefore, the end portions 32 and 34- space theplate portion 24 from the :boom llt when the base member 20 is mountedon the boom 10. Thus mounted on boom 10, plate surface 26 issubstantially parallel to the axis of boom 10.

Plate surface 26 has an identation 50 therein defined by a flat bottom52 and two oppositely facing and upstanding abutment surfaces 54 and 56,respectively. Abutment surfaces 54 and 56 are generally parallel to eachother and generally perpendicular to the plate surface 26. Further,abutment surfaces 54 and 56 extend from the central portion defined bythe line 58 f FIGS. 3 and 4 to a position adjacent end portion 32.Bottom 52 of the indentation t slopes gradually downwardly toward theboom when the base member 2t is mounted thereon from the line 58 towardend poriton 32. This sloping of the bottom 52 provides that the abutmentsurfaces 54 and S6 gradually increase in height in the direction fromthe line 58 toward end portion 32 such that the abutment surfaces 54 and56 have their greatest depth adjacent to the end portion 32. Positionedadjacent to end portion 34 in plate portion 24- is an opening 69 throughwhich rivet 22 passes to mount base member 2t onto boom 10, asaforementioned. Positioned on opposite sides of opening 66 are two.raised knobs 62 and 64 which are conventionally provided to aid in thesecurance of the element 14, as will be hereinafter mentioned Thereinforcement and stiffening of the member 24 by the flanges 36 and 38is sutficient to prevent the member 24 from bowing under the clampingforce of the rivet 22. If such bowing did occur, it is obvious that theclamping force would be relieved and thereby reduce the force whichotherwise would hold the assembly in a selected position. If the forceis too weak, obviously the tongue portion 66 will not be retained in theindentation 5f nor will the element be held securely enough onto theboom 10.

In a specific embodiment of this invention, the base member 20ismanufactured of aluminum sheet which is one-sixteenth inch thick.Plate portion 24 measures approximately one and one-quarter inches byone and one-quarter inches and has attached, as aforementioned, twoflange portions 36 and 38 which depend from the plate portion 24 adistance of three-sixteenths of an inch. End portions 32 and 34,however, depend from the plate portion 24 a distance of approximatelyfive-sixteenths of an inch. The surfaces 44 and 46 of the end portions32 and 34, respectively, at their closest point to the plate portion 24,extend two-sixteenths of an inch below the plate portion 24. Thus, whenthe base member 2b is mounted on the boom 10, the plate portion 24 is atleast tWo-sixteenths of an inch away from the exterior surface of theboom it however, due to the cylindrical shape of the boom 19, the flangeportions 36 and 38 are spaced farther apart from the boom ltl. Surfaces4-4- and 46 are radiused substantially identically with the boom 10. Theindentation 56 of the base member 29 measures approximately one inchtransversely of the base member 20 and one half inch measured from theline 53 to the position at which the abutment surfaces 54 and 56terminate adjacent to end 32.

As illustrated, base member 20 is integrally formed of material having aconstant thickness. In a specific construction, base member 20 has beenmade of aluminum sheet; however, any sheet metal or other materialhaving suitable strength and other physical properties would be equallysatisfactory, keeping in mind that the devices 16 of this invention areexposed to the weather and therefore are preferably corrosion resistant.

In operation, the base member 20 of the device .16 of this invention ismounted on boom 10, as shown in FIG. 2, with a cap member 18 positionedon surface 26. Cap member 18 has a resilient tongue portion 66 and acylindrical portion 68. The cylindrical portion is dimensioned andshaped so as to fit intimately over element 14. Tongue portion 66 isresilient and extends away from the cylindrical portion 68 generallyperpendicularly, and further, is rectangular in shape and of the samedimensions. substantially as the indentation for reasons that willbecome obvious hereinafter. Tongue portion 66 has oppositely facingedges 78 and 72 and has a flat, down wardly facing surface 71 restingupon surface 26 of the plate portion 24.

Referring now to FIGS. 2, 8 and 9, there is shown an element 14 securedto the boom 10 by the fastening device 16 of this invention. Intimatelyfitted into the cylindrical portion 68 of cap member 18 is a tubularelement 1%. Cap member 18 is positioned intermediate the ends of element14 and with the element 14 held between the cap member 18 and the basemember 20. Cap member 18 is also in contact with surface 26 of the basemember 20 and is secured thereto by pin or rivet 22 which passes throughthe cylindrical portion 68 of the cap 18 and the opening of the basemember 20. Pin

22 also passes through the element 14 and the boom 10, and forciblyclamps the cap member 18, the base member 20, the element 14 and theboom between enlarged end portions 72 and 74, shown in FIGS. 8 and 9.Thus secured together, the element 14 and the cap member 18 areincapable of movement with respect to each other and form a firstpivotal unit 76; and similarly, the base member 20 and the boom 10 areincapable of movement with respect to each other and form a secondpivotal unit 78. Pivotal units 76 and 78 are movable with respect toeach other from a first position, illustrated in FIG. 8, in which thetongue portion 66 extends transversely of the boom 10 and the element 14is generally parallel to the axis 48 of boom 10, to a second position,illustrated in FIGS. 2 and 9, in which the element 14 is substantiallyperpendicular to the boom 10 and the tongue portion 66 is positioned inthe indentation 50* of the base portion 20 with the tongue edges 70 and72 engaged with the abutment surfaces 54 and 56. Thus, it can be seenthat tongue 66 in the indentation 50 forms a detent device for holdingthe element 14 in the second position above-mentioned.

Since all of the base members 20 are secured to the boom 10 in spacedapart relationship in an identical manner, each element 14 of theantenna will be substantially perpendicular to the boom and parallel toeach other when the tongue portions 66 thereof are positioned within therespective indentations 50. Further, since the cylindrical portions 68of cap members 18 intimately fit the respective elements 14 and thecylindrical surfaces of base members 20 are coaxially positioned on theboom 10, each element 14 is rigidly secured in the aforementionedposition by engagement of the tongue member 66 with the respectiveindentation 50.

In moving the pivotal unit 76 from the position shown in FIG. 8 to theposition shown in FIG. 9, the camming surfaces 40 and 42 of flangeportions 3-6 and 38 function to allow the cap member 18 to rotaterelative to the base member 20 with relative ease. As can be seen fromFIG. 8, when the cap member 18 is positioned in the first positionabove-mentioned with tongue member 66 extending transversely of the boom10, a portion of the tongue member 66 depends beneath the plane of thesurface 26 of the base member 20 (indicated by the dotted line 80).Thus, the tongue portion 66 of cap member 18 mustbe lifted onto thesurface 26 of the base member 20 when the cap member 18 is rotated fromthe first position, shown in FIG. 8, to the second position, shown inFIG. 9. This is the function of the camming surfaces 40 and 42 of theflange portions 36 and 38. During the rotation above-mentioned, one ofthe edges 70, 72 of the tongue portion 66 engages one of the roundedcamming surfaces 40 and 42 and is lifted onto surface 26 of the basemember 20 and into the indentation 50. Further, with the cap member 18in the first position above-mentioned, as illustrated in FIG. 8, element14 is positioned between knobs 62 and 64 formed in the surface 26; andthus, when the element 14 is moved into the second position, illustratedin FIG. 9, the element 14 is lifted from the surface 26 and onto theknobs 62 and 64 thereby urging the cap member 18 and the base member 20apart and aiding in the securance of the element 14 to the cap member 18and the base member 20 to the boom 10, respectively.

The improved device for pivotally connecting each of the elements 14 ofthe antenna to the antenna boom 10 of this invention thus provides thatthe elements 14 can be positioned in a generally parallel position tothe axis of the boom 10 and moved when desired into a position generallyperpendicular to the boom. In this latter position, the elements 14 arerigidly secured to the boom and locked into position by the detentdevice comprising the indentation 50 and the tongue portion 66above-mentioned. Further, each of the elements 14 are generally parallelto each other in the last-mentioned position since each of the basemembers 20 and cap members 18 are substantially identical and can onlyfit boom 10 and the element 14, respectively, in the positionillustrated in the drawings. Further, the base 20 is strengthened byflanges 36 and 38 such that the surface 26 does not become bowed whenthe element 14, the cap 18, the base 20 and the boom 10 are connectedtogether during the manuf-acture of the antenna or when the element 14is rotated into operating position during which the clamping force isincreased by the action of the knobs 62 and 64, as aforementioned. Thus,the tongue portion 70 fits the indentation 50 as intended and theelement 14 is rigidly secured to the boom 10, as intended, and will notbecome loosened because of the bowing of the base member 20. Stillfurthenthe rotation of the element 14 with respect to the boom 10 ismade easier by means of the camming surfaces 48 and 42 of the flanges 36and 38 as aforementioned. This provides that rotation of element 14 intothe locked position, in which element 14 is substantially perpendicularto the boom 10, can be achieved relatively easily and without bending ofboom 10 or element 14.

While there have been described above the principles of this inventionin connection with specific apparatus, it is to be clearly understoodthat this description is made only by way of example and not as alimitation to the scope of this invention.

What is claimed is:

1. For use in an antenna comprising an elongated and cylindrical boomand a plurality of elongated antenna elements, a plurality of devicespivotally connecting each of said elements to said boom, respectively,each of said devices including a base member mounted on said boom and acap member positioned on and pivotally connected to said base member,said base member having a flat metal plate portion of substantiallyrectangular shape; said plate portion having a flat surface facing awayfrom said boom, opposite and parallel longitudinal edges and oppositeend portions, two strengthening and reinforcing flange portionsintegrally joined to said plate portion adjacent to said opposite edges,respectively, and extending generally perpendicularly away from saidplate portion toward said boom; said flange portions extending betweensaid end portions and having oppositely and outwardly facing roundedcamming surfaces, respectively joining and smoothly merging into saidplate surface at said longitudinal edges, said end portions extendinggenerally perpendicularly away from said plate portion toward said boomand beyond said flange portions, each of said end portions having a partcylindrical surface coaxially posi tioned on said boom and spaced fromsaid plate portion, thereby spacing said plate portion from said boom,said plate surface being substantially parallel to the axis of said boomand having an indentation therein defined by a flat bottom andoppositely facing and upstanding abutment surfaces, said abutmentsurfaces being generally perpendicular to said plate surface andextending from the central portion of said plate portion to one of saidend portions, said bottom sloping toward said boom and said one endportion, whereby said abutment surfaces gradually increase in depth inthe direction from the center of said plate portion to said one endportion, said abutment surfaces having the greatest depth dimensionadjacent to said one end portion, said cap member including apart-cylindrical portion which fits intimately over said antenna elementand a resilient tongue portion extending in a direction normal to theaxis of said partcylindrical portion, said tongue portion being flat andrectangular in shape, said tongue portion further being of a size andshape as to fit intimately said indentation in said base member, saidcap member and said element as a unit being superposed onto the platesurface of said base member, a pivot pin extending through said capmember, said element, said base member and said boom and forcefullyclamping the same together, said flanges on said base member being ofsuch size and strength that said plate portion is not bowed toward saidboom by the clamping force of said pivot pin, said cap member andantenna element being rotatable from a first position in which saidelement is generally parallel to said boom and said tongue portionextends transversely of said boom and one of said camming surfaces to asecond position in which said antenna element is substantiallyperpendicular to said boom and said tongue portion is positioned in saidindentation with the tongue edges engaged with said abutment surfaces,respectively, whereby said tongue portion and said indentation form adetent device for holding said cap member and said base member againstrotation, said tongue portion being disposed beneath said plate surfacewhen said cap member is in said first position whereby one of saidtongue portion edges engages one of said camming surfaces of said basemember and lifts said tongue portion onto said plate surface during therotation of said cap member from said first position to said secondposition.

2. For use in an antenna, an elongated and cylindrical boom and aplurality of elongated antenna elements, a plurality of devicespivotally connecting each of said elements to said boom, respectively,each of said devices including a base member mounted on said boom and acap member positioned on and pivotally connected to said base member,said base member having a flat metal plate portion with a flat surfacewhich faces away from said 'boo'm, said plate portion having oppositelongitudinal edges and opposite end portions, two strengthening andreinforcing flange portions integrally joined to said plate portionadjacent to said opposite edges, respectively, and extending generallyperpendicularly away from said plate portion toward said boom, saidflange portions having oppositely and outwardly facing earning surfaces,respectively, joining said plate surface at said longitudinal edges,said camming surfaces being rounded and smoothly merging with said flatsurface and said flanges whereby said camming surfaces and said platesurface are continuous, said end portions extending generallyperpendicularly away from said plate portion toward said boom, each ofsaid end portions having a part-cylindrical surface positioned on saidboom and spaced from said plate portion, thereby spacing said plateportion from said boom, said plate portion having an indentation thereindefined by oppositely facing and upstanding abutment surfaces,

said cap member including a part-cylindrical portion which fitsintimately over said antenna element and a resilient tongue portionextending in a direction normal to the axis of said part-cylindricalportion, said tongue portion being flat and rectangular in shape, saidtongue portion further being of a size and shape as to fit intimatelysaid indentation in said base member, said cap member and said elementas a unit being superposed onto the plate surface of said base member, apivot pin extending through said cap member, said element, said basemember and said boom and forcefully clamping the same together, saidflanges on said base member being of such :size and strength that saidplate portion is not bowed toward said boom by the clamping force ofsaid pivot pin, :said cap member and element being movable from a firstposition in which said element is generally parallel to :said boom andsaid tongue portion of said cap member extends transversely of said boomto a second position in which said element is substantiallyperpendicular to said "boom and said tongue portion is positioned insaid indentation with said tongue edges engaged with said abutmentsurfaces, whereby said tongue and indentation form a detent device forholding said first and second pivotal units against rotation, saidtongue portion being disposed beneath said plate surface when said capmember is in said first position whereby one of said tongue portion tedges engages one of said camming surfaces of said base member and liftssaid tongue portion onto said plate sur- 8 face during the rotation ofsaid-cap member from said first position to said second position.

3. For use in an antenna, a base member having a flat metal plateportion of substantially rectangular shape provided with a flat surface,said plate portion having opposite and parallel longitudinal edges andopposite end portions, two strengthening and reinforcing flange portionsintegrally joined to said plate portion adjacent to said opposite edges,respectively, and extending generally perpendicularly away from saidplate portion in one direction, said flange portions extending betweensaid end portions and having oppositely and outwardly facing cammingsurfaces, respectively, joining said plate surface at said longitudinaledges, said camming surfaces being rounded and smoothly merging withsaid flat surface and said flanges whereby said camming surfaces andsaid plate surface are continuous, said end portions extending generallyperpendicularly away from said plate portions in said one direction andbeyond said flange portions, each of said end portions having apart-cylindrical surface spaced from said plate portion, said platesurface having an indentation therein defined by a flat bottom andoppositely facing and upstanding abutment surfaces, said abutmentsurfaces being generally perpendicular to said plate surface andextending from the central portion of said plate portion to one of saidend portions, said bottom sloping downwardly toward said one endportion, whereby said abutment surfaces gradually increase in depth inthe direction from the center of said plate portion to said one endportion, said abutment surfaces having the greatest depth dimensionadjacent to said one end portion.

4. For use in an antenna, a base member having a flat metal plateportion with a flat surface, said plate portion having oppositelongitudinal edges and opposite end portions, two strengthening andreinforcing flange portions integrally joined to said plate portionadjacent to said opposite edges, respectively, and extendingperpendicularly away from said plate portion in one direction, saidflange portions having oppositely and outwardly facing camming surfaces,respectively, joining said plate surface at said longitudinal edges,said camming surfaces being rounded and smoothly merging with said flatsurface and said flanges whereby said camming surfaces and said platesurface are continuous, said end portions extending generallyperpendicularly away from said plate portions in said one direction,each of said end portions having a partcylindrical surface spaced fromsaid plate portion, said plate portion having an indentation thereindefined by oppositely facing and upstanding abutment surfaces.

5. For use in an antenna, a structure comprising a base member and a capmember positioned on and pivotally connected to said base member, saidbase member having a flat metal plate portion of substantiallyrectangular shape with a flat surface, said plate portion havingopposite and parallel longitudinal edges and opposite end portions, twostrengthening and reinforcing flange portions integrally joined to saidplate portion adjacent to said opposite edges, respectively, andextending generally perpendicularly away from said plate portion andsaid cap member, said flange portions extending between said endportions and having oppositely and outwardly facing camming surfaces,respectively, joining said plate surface at said longitudinal edges,said camming surfaces being rounded and smoothly merging with saidflat'surface and said flanges whereby said camming surfaces and saidplate surface are continuous, said end portions extending generallyperpendicularly away from said plate portion in the same direction andbeyond said flange portions, each of said end portions having apart-cylindrical surface spaced from said plate portion, said platesurface being substantially parallel to the axis of saidpart-cylindrical surfaces and having an indentation therein defined by aflat bottom and oppositely facing and upstanding abutmeat surfaces, saidabutment surfaces being generally perpeudicular to said plate surfaceand extending from the central portion of said plate portion to one ofsaid end portions, said bottom sloping away from said cap and towardsaid one end portion, whereby said abutment surfaces gradually increasein depth in the direction from the center of said plate portion to saidone end portion, said abutment surfaces having the greatest depthdimension adjacent to said one end portion, and pin means extendingthrough said cap member and base member for forcefully clamping said capmember and base member together and for pivotally connecting said capmember to said base member, said cap member having a resilient tongueportion, said tongue portion being rectangular in shape and havingoppositely facing edges, said cap member being movable from a firstposition in which said tongue portion extends transversely of said basemember to a second position in which said tongue portion is positionedin said indentation with said tongue edges engaged with said abutmentsurfaces, whereby said tongue portion and indentation form a detentdevice for holding said cap member and base member against rotation,said tongue portion being disposed beneath said plate surface when saidcap member is in said first position whereby one of said tongue portionedges engages one of said camming surfaces of said base member and liftssaid tongue portion onto said plate surface during the rotation of saidcap member from said first position to said second position.

6. For use in an antenna, a base member and a cap member positioned onand pivotally connected to said base member, said base member having aflat metal plate portion with a flat surface which faces toward said capmember, said plate portion having opposite longitudinal edges andopposite end portions, two strengthening and reinforcing flange portionsintegrally joined to said plate portion adjacent to said opposite edges,respectively, and extending generally perpendicularly away from saidplate portion and said cap member, said flange portions havingoppositely and outwardly facing camming surfaces, respectively, joiningsaid plate surface at said longitudinal edges, said camming surfacesbeing rounded and smoothly merging with said flat surface and saidflanges whereby said camming surfaces and said plate surface arecontinuous, said end portions extending generally perpendicularly awayfrom said plate portion in the same direction and beyond said flangeportions, each of said end portions having a part-cylindrical surfacespaced from said plate portion, said plate portion having an indentationtherein defined by oppositely facing and upstanding abutment surfaces,and pin means extending through said cap member and base member forforcefully clamping said cap member, and said base member together andfor pivotally connecting said cap member to said base member, said capmember having a resilient tongue portion, said tongue portion havingoppositely facing edges, said cap member being movable from a firstposition in which said tongue portion of said cap member extendstransversely of said base member to a second position in which saidtongue portion is positioned in said indentation with said tongue edgesengaged with said abutment surfaces, whereby said tongue and indentationform a detent device for holding said first and second pivotal unitsagainst rotation, said tongue portion being disposed beneath said platesurface when said cap member is in said first position whereby one ofsaid tongue portion edges engages one of said camming surfaces of saidbase member and lifts said tongue portion onto said plate surface duringthe rotation of said cap member from said first position to said secondposition.

No references cited.

HERMAN KARL SAALBACH, Primary Examiner.

R. F. HUNT, Assistant Examiner.

6. FOR USE IN AN ANTENNA, A BASE MEMBER AND A CAP MEMBER POSITIONED ONAND PIVOTALLY CONNECTED TO SAID BASE MEMBER, SAID BASE MEMBER HAVING AFLAT METAL PLATE PORTION WITH A FLAT SURFACE WHICH FACES TOWARD SAID CAPMEMBER, SAID PLATE PORTION HAVING OPPOSITE LONGITUDINAL EDGES ANDOPPOSITE END PORTIONS, TWO STRENGTHENING AND REINFORCING FLANGE PORTIONSINTEGRALLY JOINED TO SAID PLATE PORTION ADJACENT TO SAID OPPOSITE EDGES,RESPECTIVELY, AND EXTENDING GENERALLY PERPENDICULARLY AWAY FROM SAIDPLATE PORTION AND SAID CAP MEMBER, SAID FLANGE PORTIONS HAVINGOPPOSITELY AND OUTWARDLY FACING CAMMING SURFACES, RESPECTIVELY, JOININGSAID PLATE SURFACE AT SAID LONGITUDINAL EDGES, SAID CAMMING SURFACESBEING ROUNDED AND SMOOTHLY MERGING WITH SAID FLAT SURFACE AND SAIDFLANGES WHEREBY SAID CAMMING SURFACES AND SAID PLATE SURFACE ARECONTINUOUS, SAID END PORTIONS EXTENDING GENERALLY PERPENDICULARLY AWAYFROM SAID PLATE PORTION IN THE SAME DIRECTION AND BEYOND SAID FLANGEPORTIONS EACH OF SAID END PORTIONS HAVING A PART-CYLINDRICAL SURFACESPACED FROM SAID PLATE PORTION, SAID PLATE PORTION HAVING AN INDENTATIONTHEREIN DEFINED BY OPPOSITELY FACING AND UPSTANDING ABUTMENT SURFACES,AND PIN MEANS EXTENDING THROUGH SAID CAP MEM-